Assuming you are a non-exempt, hourly employee, your first step is to question your manager and bring the discrepancy to their attention. If the situation is not corrected, you can contact the state or federal Department of Labor and discuss the situation with a representative. Not paying an hourly employee for hours worked is illegal.

You are going to need to take this up with your employer. First off, ask them where your money is. If they won't give it to you, you are going to need to contact your local labor board or hire an attorney.